Low contribution of the fast-sinking particle fraction to total plankton metabolism in a temperate shelf sea

García‐Martín, E. E., Davidson, K., Davis, C. E., Mahaffey, C., McNeill, S., Purdie, D. A. and Robinson, C. (2021) Low contribution of the fast-sinking particle fraction to total plankton metabolism in a temperate shelf sea. Global Biogeochemical Cycles, 35 (9). ISSN 0886-6236

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Abstract

Temperate shelf seas are productive areas with the potential to export high quantities of particulate organic carbon (POC), as sinking particles, to the sediments or off-shelf to the open ocean. The amount of carbon which can be exported depends partly on the amount of POC produced and on the remineralization processes occurring on the sinking material. Here, we assessed the relative seasonal importance of microbial respiration and bacterial production associated with suspended, slow- and fast-sinking particle fractions. The three fractions were collected in the Celtic Sea above and below the seasonal thermocline in November 2014, April and July 2015 using Marine Snow Catchers. The slow-sinking fraction had higher microbial respiration and bacterial production rates than the fast-sinking fractions, and these two fractions sustained rates of microbial respiration and bacterial production between 1 and 3 orders of magnitude lower than the suspended fraction. This low contribution of the slow- and fast-sinking fractions was consistent with their low contribution to the POC concentration at the two depths sampled. The POC-specific respiration rates associated with the slow- and fast-sinking fractions were low (median 0.17 and 0.08 d−1, respectively), indicating low-sinking particle degradation. Our results indicate that ∼5% of the POC in surface waters can be exported below the thermocline.

Item Type: Article
Uncontrolled Keywords: sdg 14 - life below water ,/dk/atira/pure/sustainabledevelopmentgoals/life_below_water
Faculty \ School: Faculty of Science > School of Environmental Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 09 Oct 2021 01:04
Last Modified: 13 Oct 2021 02:16
URI: https://ueaeprints.uea.ac.uk/id/eprint/81635
DOI: 10.1029/2021GB007015

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